GOP ponders tax options for debt 'supercommittee'

"We've made a little bit of progress but it's not enough, in our judgment," said Sen. John Kerry, D-Mass., a member of the deficit panel. "We have some distance to go."

Republicans are asking a high price - cuts to important benefit programs like Medicare and Medicaid - in exchange for potential revenue hikes. Democrats are pressing for more than $1 trillion in revenue over the coming decade.

"I have yet to see a real, credible plan that raises revenue in a significant way to bring use to a fair, balanced proposal," said Sen. Patty Murray, D-Wash., the panel's co-chair.